Ignition Timing Advance vs Knock Sensor Operation
07-17-2003, 10:44 AM
#1
Dyno plot says I have the most area under the Administrator curve
Thread Starter
Join Date: Jul 2001
Posts: 7,060
Ignition Timing Advance vs Knock Sensor Operation
I've done a fair amount of driving with my Palm OS OBD-II Scanner feeding me live data with my knock sensor in various states of operation.
- Working.
- Partially working.
- Not working at all.
- Bypassed via 470k resistor.
The knock sensor is very key to performance in this car because it tells the ECU how much ignition timing advance it can run. The more advance the better. But if the knock sensor is dead, the ECU will know this and go into a sort of safe ignition advance mapping in which your performance will just plain suck and the engine won't have much pull. 5spd guys will not notice this as much due to shorter and more aggressive gearing, but it would be especially noticeable in the automatic which has very widely spaced and long gears. So if you own a 95-99 Maxima and it just seems to have lost a lot of pep, chances are good that you knock sensor may be bad. The following info may be useful to you...
I will now try to explain the amount of ignition advance you should be getting and what you will "feel" in relation to all of this.
WORKING KNOCK SENSOR
Here is what your ignition timing advance should look like if your knock sensor is working properly.
Ignition Advance vs Throttle Position
During cruising at very light throttle, the ECU wants to run as much timing advance as possible. This helps the engine as far as being responsive and also probably helps out with emissions as well. 30-40 degrees of advance. Of course, when you get on it you are increasing the pressures in the cylinder (increasing the likelihood of detonation) and may not be able to run that much advance, so the default ignition map goes down to 20-30 degrees depending on how much throttle you're giving it. When you go WOT, or very close to WOT, there appears to be another map just for this. At WOT and lower RPM's you timing advance will start out in the mid-teen range and then slowly ramp up to the low/mid-20 degree range as you approach redline. As the engine spins quicker, it needs more advance to perform the best.
To those of you that really need to see things, here is something that may help you visualize all of this. Below is some raw data from my OBD-II scanner that I converted into a pretty Excel chart of a highway ramp acceleration run.
From samples 220-232 I am cruising up an uphill ramp in 3rd gear (5spd) playing with the throttle a bit to try and capture as much of the ECU's ignition mapping as possible. You can see that the ignition advance is varying between about 30-40 degrees with as much as 15% throttle.
Right at sample 232 or so I am at the top of the ramp. You can see that my speed remained steady at around 30 mph, but my RPM's jumped up from 2000rpm to 3000rpm. This is me seeing that traffic is completely clear, so I downshifted to 2nd for a WOT run. WOT registers at about 93%, and you can see that the ignition advance went down to maybe 16-17 degrees and slowly ramped up as the revs climbed to about 25 degrees @ 5500rpm when I shifted. The 2-3 shift landed me at about 4500rpm and ignition advance went to about 18-19 degrees and then ramped up to maybe 24 degrees @ 5500rpm and 85 mph
when I backed off. You can see that throttle position dropped to about 85%, as I was not quite at full throttle, yet the ignition timing still remained at a "near WOT" condition where it gives you the same timing as full WOT would.
At sample 246 I skipped from 3rd to 5th and then just toyed with the throttle for a mile or so. As you can see once again, during cruise and light throttle the ECU wants to run as much timing as possible. 40-45 degrees appears to be the maximum advance. During acceleration the advance will be anywhere from 20-40 degrees, depending on how much throttle you are giving it. Anything from about 30% throttle and up (before the WOT map) should give you somewhere around the low/mid-20 degrees of advance, but it may drop to 18 degrees momentarily. (this observation will be important later
)
During all of this the engine should feel torquey and responsive just like it should.
NON-WORKING KNOCK SENSOR
If your knock sensor is blown or disconnected, the ECU will know this and throw a "silent" trouble code, meaning it will NOT light the SES/CEL light on your dash. If you put your ECU into diagnostic mode it will give you an "0304" code for the Knock Sensor, or with an OBD-II scanner you will get P0325 which is the same thing.
With the knock sesnor either dead or disabled, the ECu will still try to run at least some ignition advance for performance and emissions, but only at very light loads. During cruising at very light throttle, I still got 30-40 degrees of advance. However, there appears to be a cut-off point at around 30% throttle where the ECU will send the timing back to a "safe map".
So what is the difference on a BUTT-DYNO? I would say EASILY 15-20 horsepower and torque at the crank. There is a BIG difference. I really had to get on it pretty hard just to out-accelerate a 4-cylinder Accord with my knock sensor blown, and that's with a 5spd too.
PARTIALLY WORKING KNOCK SENSOR
There really isn't much to explain here, except to just warn you that your car will be extremely annoying to drive because it will not perform consistently.
Even with your ECU throwing a knock sensor ghost code, it could still be on either the default optimized ignition map or the safe map for a blown KS at anytime and without notice. If it is getting invalid readings from your KS it may put the car in the safe map. If it is clear for say 5 minutes, it may put it back on the default "optimized" map until it gets invalid readings again. The result is that when you put your foot down as you're trying to merge and are expecting a certain amount of power to complete a maneuver, you may or may not get it and you could get yourself into trouble! This really drove me nuts commuting through really heavy DC traffic and made me uneasy about my car.
Proof of this is in one of my data logs. At the beginning of my trip home from work I went WOT in 3rd gear and got the optimized 15-25 degree range of advance and the engine felt very zippy with plenty of pull. Yet just 10-15 minutes later I accelerated in the same exact way and got a max of only 10 degrees of ignition advance and there wasn't nearly as much pull. So you never know what to expect. Not an enjoyable driving experience by any means...
My knock sensor has been slowly dying for the past few months. It started out just going into this safe map once in awhile but mostly being on the optimized map. Then it just slowly transitions from that, to about 50/50, to being completely blown and on the safe map 100% of the time. I cleaned up the grounds of the sensor (see www.motorvate.ca for reference) and that helped a lot, but only extended the life of the sensor a few more days until it completely died.
BYPASSED OPERATION VIA 470K RESISTOR
If you locate the knock sensor sub-harnass and disconnect it, you can stick a standard 470k leaded resistor into the connector and then tape it into place. Since the "no knocking" resistance of the knock sensor is 470k, putting this resistor in is how you fake out the ECU into thinking that everything is okay as a temporary fix until you can get your knock sensor replaced. This will get you back on the performance (default) ignition timing map and your car will not feel like a slug anymore.
*** WARNING: THINGS TO BE AWARE OF WITH THE RESISTOR "FIX" ***
This bypass resistor fix effectively removes the safety net that the engine has, so YOU are now the "knock sensor" and need to take appropriate action if your engine starts knocking.
Remember above where I said...
...???
As it turns out IT IS POSSIBLE TO GET KNOCKING EVEN WITH PREMIUM FUEL WITH THE BYPASS RESISTOR.
Under certain conditions such as very high summer temperatures, or if you have a lot of mods, the default ignition map may be a bit too aggressive and the engine may start knocking. Since the car is now operating "open-loop" (not-controlled) without the knock sensor, there is nothing to tell the ECU to trim back the timing a bit to avoid the knocking and protecting the engine. You need to listen carefully for this and if you get some knocking, determine if it is severe enough to do anything about it.
Running yesterday with my bypass resistor installed, I DID get some extremly mild knocking at about 3400 rpm (peak torque on a 4th Gen) when accelerating moderately (timing still at 20-30 degrees) with the OBD-II scanner reading Intake Air Temperatures at about 95F. If the knock sensor was working and in place, the ECU would have trimmed timing back to about 18 degrees to avoid the knock, and then re-advance back into the 20 degree range. The pinging I heard was extremely mild and nothing to be concerned about. All engines are more than able to take a little pinging and the VQ has proven to be a very tough and durable engine. This morning I monitored everything again, and the IAT read only 80F, 15 degrees cooler than yesterday. No pinging/knocking ("ping" is a more accurate description of the sound) whatsoever.
But my car is stock. If you have a modded Maxima you may get more pinging than me, especially when combined with high temperature heat-soaked conditions. Just monitor this and keep your stereo volume lower and be aware of what could happen. It goes without saying that you should run nothing but premium fuel with this bypass fix. If multiple people drive your car and someone puts 87 in it you could be in trouble. In that case I would probably not even bypass at all, as that is a recipe for disaster. If you live in an area such as California where the highest you can get is 91 octane and it also gets rather hot, you will need to be even more careful. Just be aware of that YOU are now the "human knock sensor".
If you have made it this far and have actually learned something and/or found this information helpful, CONGRATS!!
SUMMARY
phweew!!
EDIT: SHIFTed_spelling/table_errors
- Working.
- Partially working.
- Not working at all.
- Bypassed via 470k resistor.
The knock sensor is very key to performance in this car because it tells the ECU how much ignition timing advance it can run. The more advance the better. But if the knock sensor is dead, the ECU will know this and go into a sort of safe ignition advance mapping in which your performance will just plain suck and the engine won't have much pull. 5spd guys will not notice this as much due to shorter and more aggressive gearing, but it would be especially noticeable in the automatic which has very widely spaced and long gears. So if you own a 95-99 Maxima and it just seems to have lost a lot of pep, chances are good that you knock sensor may be bad. The following info may be useful to you...
I will now try to explain the amount of ignition advance you should be getting and what you will "feel" in relation to all of this.
WORKING KNOCK SENSOR
Here is what your ignition timing advance should look like if your knock sensor is working properly.
Ignition Advance vs Throttle Position
- Coasting: 0 degrees
- Idle: 8-15 degrees.
- Cruising: (<10% throttle), 30-40 degrees
- Mild Acceleration: (10-20% throttle), 30 degrees or so.
- Moderate Acceleration: (20-40% throttle), low to mid 20 degree range, may drop to about 18 momentarily.
- Hard Acceleration: (40-xx% throttle but not WOT or "near WOT"): same as above.
- WOT or "Near WOT" Acceleration: approx 15-25 degrees, RPM dependent.
During cruising at very light throttle, the ECU wants to run as much timing advance as possible. This helps the engine as far as being responsive and also probably helps out with emissions as well. 30-40 degrees of advance. Of course, when you get on it you are increasing the pressures in the cylinder (increasing the likelihood of detonation) and may not be able to run that much advance, so the default ignition map goes down to 20-30 degrees depending on how much throttle you're giving it. When you go WOT, or very close to WOT, there appears to be another map just for this. At WOT and lower RPM's you timing advance will start out in the mid-teen range and then slowly ramp up to the low/mid-20 degree range as you approach redline. As the engine spins quicker, it needs more advance to perform the best.
To those of you that really need to see things, here is something that may help you visualize all of this. Below is some raw data from my OBD-II scanner that I converted into a pretty Excel chart of a highway ramp acceleration run.
From samples 220-232 I am cruising up an uphill ramp in 3rd gear (5spd) playing with the throttle a bit to try and capture as much of the ECU's ignition mapping as possible. You can see that the ignition advance is varying between about 30-40 degrees with as much as 15% throttle.
Right at sample 232 or so I am at the top of the ramp. You can see that my speed remained steady at around 30 mph, but my RPM's jumped up from 2000rpm to 3000rpm. This is me seeing that traffic is completely clear, so I downshifted to 2nd for a WOT run. WOT registers at about 93%, and you can see that the ignition advance went down to maybe 16-17 degrees and slowly ramped up as the revs climbed to about 25 degrees @ 5500rpm when I shifted. The 2-3 shift landed me at about 4500rpm and ignition advance went to about 18-19 degrees and then ramped up to maybe 24 degrees @ 5500rpm and 85 mph
when I backed off. You can see that throttle position dropped to about 85%, as I was not quite at full throttle, yet the ignition timing still remained at a "near WOT" condition where it gives you the same timing as full WOT would.At sample 246 I skipped from 3rd to 5th and then just toyed with the throttle for a mile or so. As you can see once again, during cruise and light throttle the ECU wants to run as much timing as possible. 40-45 degrees appears to be the maximum advance. During acceleration the advance will be anywhere from 20-40 degrees, depending on how much throttle you are giving it. Anything from about 30% throttle and up (before the WOT map) should give you somewhere around the low/mid-20 degrees of advance, but it may drop to 18 degrees momentarily. (this observation will be important later
) During all of this the engine should feel torquey and responsive just like it should.
NON-WORKING KNOCK SENSOR
If your knock sensor is blown or disconnected, the ECU will know this and throw a "silent" trouble code, meaning it will NOT light the SES/CEL light on your dash. If you put your ECU into diagnostic mode it will give you an "0304" code for the Knock Sensor, or with an OBD-II scanner you will get P0325 which is the same thing.
With the knock sesnor either dead or disabled, the ECu will still try to run at least some ignition advance for performance and emissions, but only at very light loads. During cruising at very light throttle, I still got 30-40 degrees of advance. However, there appears to be a cut-off point at around 30% throttle where the ECU will send the timing back to a "safe map".
- Cruising: 30-40 degrees (like before)
- Light to mild/moderate Acceleration: (10-30% throttle), low-20 degree range.
- ANYTHING above that: ( >30% throttle), 5-12 degrees
So what is the difference on a BUTT-DYNO? I would say EASILY 15-20 horsepower and torque at the crank. There is a BIG difference. I really had to get on it pretty hard just to out-accelerate a 4-cylinder Accord with my knock sensor blown, and that's with a 5spd too.
PARTIALLY WORKING KNOCK SENSOR
There really isn't much to explain here, except to just warn you that your car will be extremely annoying to drive because it will not perform consistently.
Even with your ECU throwing a knock sensor ghost code, it could still be on either the default optimized ignition map or the safe map for a blown KS at anytime and without notice. If it is getting invalid readings from your KS it may put the car in the safe map. If it is clear for say 5 minutes, it may put it back on the default "optimized" map until it gets invalid readings again. The result is that when you put your foot down as you're trying to merge and are expecting a certain amount of power to complete a maneuver, you may or may not get it and you could get yourself into trouble! This really drove me nuts commuting through really heavy DC traffic and made me uneasy about my car.
Proof of this is in one of my data logs. At the beginning of my trip home from work I went WOT in 3rd gear and got the optimized 15-25 degree range of advance and the engine felt very zippy with plenty of pull. Yet just 10-15 minutes later I accelerated in the same exact way and got a max of only 10 degrees of ignition advance and there wasn't nearly as much pull. So you never know what to expect. Not an enjoyable driving experience by any means...
My knock sensor has been slowly dying for the past few months. It started out just going into this safe map once in awhile but mostly being on the optimized map. Then it just slowly transitions from that, to about 50/50, to being completely blown and on the safe map 100% of the time. I cleaned up the grounds of the sensor (see www.motorvate.ca for reference) and that helped a lot, but only extended the life of the sensor a few more days until it completely died.
BYPASSED OPERATION VIA 470K RESISTOR
If you locate the knock sensor sub-harnass and disconnect it, you can stick a standard 470k leaded resistor into the connector and then tape it into place. Since the "no knocking" resistance of the knock sensor is 470k, putting this resistor in is how you fake out the ECU into thinking that everything is okay as a temporary fix until you can get your knock sensor replaced. This will get you back on the performance (default) ignition timing map and your car will not feel like a slug anymore.
*** WARNING: THINGS TO BE AWARE OF WITH THE RESISTOR "FIX" ***
This bypass resistor fix effectively removes the safety net that the engine has, so YOU are now the "knock sensor" and need to take appropriate action if your engine starts knocking.
Remember above where I said...
Originally posted by SteVTEC
Anything from about 30% throttle and up (before the WOT map) should give you somewhere around the low/mid-20 degrees of advance, but it may drop to 18 degrees momentarily. (this observation will be important later)
Anything from about 30% throttle and up (before the WOT map) should give you somewhere around the low/mid-20 degrees of advance, but it may drop to 18 degrees momentarily. (this observation will be important later)
As it turns out IT IS POSSIBLE TO GET KNOCKING EVEN WITH PREMIUM FUEL WITH THE BYPASS RESISTOR.
Under certain conditions such as very high summer temperatures, or if you have a lot of mods, the default ignition map may be a bit too aggressive and the engine may start knocking. Since the car is now operating "open-loop" (not-controlled) without the knock sensor, there is nothing to tell the ECU to trim back the timing a bit to avoid the knocking and protecting the engine. You need to listen carefully for this and if you get some knocking, determine if it is severe enough to do anything about it.
Running yesterday with my bypass resistor installed, I DID get some extremly mild knocking at about 3400 rpm (peak torque on a 4th Gen) when accelerating moderately (timing still at 20-30 degrees) with the OBD-II scanner reading Intake Air Temperatures at about 95F. If the knock sensor was working and in place, the ECU would have trimmed timing back to about 18 degrees to avoid the knock, and then re-advance back into the 20 degree range. The pinging I heard was extremely mild and nothing to be concerned about. All engines are more than able to take a little pinging and the VQ has proven to be a very tough and durable engine. This morning I monitored everything again, and the IAT read only 80F, 15 degrees cooler than yesterday. No pinging/knocking ("ping" is a more accurate description of the sound) whatsoever.
But my car is stock. If you have a modded Maxima you may get more pinging than me, especially when combined with high temperature heat-soaked conditions. Just monitor this and keep your stereo volume lower and be aware of what could happen. It goes without saying that you should run nothing but premium fuel with this bypass fix. If multiple people drive your car and someone puts 87 in it you could be in trouble. In that case I would probably not even bypass at all, as that is a recipe for disaster. If you live in an area such as California where the highest you can get is 91 octane and it also gets rather hot, you will need to be even more careful. Just be aware of that YOU are now the "human knock sensor".
If you have made it this far and have actually learned something and/or found this information helpful, CONGRATS!!
SUMMARY
- Knock Sensor working: Optimized timing map, should never hear any knocking, consistent performance.
- Knock Sensor bad but still connected: "Safe" ignition map, cruising performance/mileage should still be okay, but anything above about 30% throttle sends your timing advance (and power) right down the toilet and your car will feel like a slug.
- Partially Working Knock Sensor = Annoying as hell due to inconsistent performance and the ECU not knowing which ignition map it should be on, but it's still safe for the engine and you shouldn't get any knocking. Be careful when merging.
- Bypassed Knock Sensor: GOOD performance due to ECU being tricked into think you have a working knock sensor. But this is the least safe because the resistor simulates a knock sensor that never hears any knock even if you DO get knock, so you need to be careful. YOU need to become a "human knock sensor". This is not foolproof. You can still get knock even if you are running premium gas, so just be careful.
phweew!!
EDIT: SHIFTed_spelling/table_errors
07-17-2003, 12:22 PM
#5
Thanks a lot Steve 
I really needed something like this because 1) I've been trying to see if the knock monitor on the SAFC 2 really works, and 2) because my dyno yesterday seems low to me.
I'll post my baseline (intake, exhaust), NA untuned, NA (tuned with SAFC), and my nitrous dynos later tonight, but now that I have timing numbers I can check my timing with my friends consult.
-hype
I really needed something like this because 1) I've been trying to see if the knock monitor on the SAFC 2 really works, and 2) because my dyno yesterday seems low to me. I'll post my baseline (intake, exhaust), NA untuned, NA (tuned with SAFC), and my nitrous dynos later tonight, but now that I have timing numbers I can check my timing with my friends consult.
-hype
07-17-2003, 02:22 PM
#9
Dyno plot says I have the most area under the Administrator curve
Thread Starter
Join Date: Jul 2001
Posts: 7,060
Originally posted by slizan99
SteVTEC, what's the name of the software that you used on your PDA?
SteVTEC, what's the name of the software that you used on your PDA?
Review of OBD-II Scan Tools for Palm OS PDAs
07-17-2003, 02:54 PM
#11
troubleshooting lagging acceleration can be tricky and we all know the KS is one of the major things to look at. We also know it can be tricky to test and monitor the KS.
But now anyone with some OBD-II tools (optimally) or anything to monitor the ignition timing should have a good roadmap on the condition of their KS. Good work steve-o!
But now anyone with some OBD-II tools (optimally) or anything to monitor the ignition timing should have a good roadmap on the condition of their KS. Good work steve-o!
07-17-2003, 03:06 PM
#12
Great write up... I wounder if you just loosen the KS bolt,if would be less sensitive (as per motorvate-KS replacement).On the other hand,what is quite interesting that the 03 Honda Accord is using regular fuel.Is the Honda engine better than our engine ? If I remember right ,our engine won some awards in the past.Correct me if Im wrong... I never had trouble with a 4 or 6 cyl sensor before..
07-18-2003, 04:32 AM
#14
Originally posted by astil
Great write up... I wounder if you just loosen the KS bolt,if would be less sensitive (as per motorvate-KS replacement).On the other hand,what is quite interesting that the 03 Honda Accord is using regular fuel.Is the Honda engine better than our engine ? If I remember right ,our engine won some awards in the past.Correct me if Im wrong... I never had trouble with a 4 or 6 cyl sensor before..
Great write up... I wounder if you just loosen the KS bolt,if would be less sensitive (as per motorvate-KS replacement).On the other hand,what is quite interesting that the 03 Honda Accord is using regular fuel.Is the Honda engine better than our engine ? If I remember right ,our engine won some awards in the past.Correct me if Im wrong... I never had trouble with a 4 or 6 cyl sensor before..
Anyway, Hondas are almost always spec'd to use regular fuel. In one test Car and Driver actually measured less HP on a V6 Accord that was filled with 93 octane.
It's in the article about octane in the FAQ.
07-18-2003, 09:40 AM
#15
Dyno plot says I have the most area under the Administrator curve
Thread Starter
Join Date: Jul 2001
Posts: 7,060
Originally posted by astil
On the other hand,what is quite interesting that the 03 Honda Accord is using regular fuel.Is the Honda engine better than our engine ?
On the other hand,what is quite interesting that the 03 Honda Accord is using regular fuel.Is the Honda engine better than our engine ?
If you want to be fair, you ought to compare the VQ30DE (released in 95) to the old Accord V6 engine, the J30A1 (released in 98). That engine was rated at 200HP on 87 octane vs 190HP on premium in the VQ. This looks awesome on paper, but when you factor in TORQUE and overall power thoughout the entire rev range, the VQ still blows the Honda V6 right out of the water. The Honda J30A1 never won any engine awards in the automotive press.
The VQ has more torque and overall power because of...
- more compression (10.0:1 vs 9.4:1)
- a knock sensor which allow much more aggressive timing (J30A1 doesn't even have a KS)
07-18-2003, 11:39 AM
#16
Very informative write-up.
Here's my question though: If we do the knock sensor bypass, is there any way to continue to use the existing knock sensor in a way that would visually show you knocking or pinging (inside the car) but it wouldn't tell the ECU. Maybe an LED or something that would come on in the event of knocking or pinging?
Here's my question though: If we do the knock sensor bypass, is there any way to continue to use the existing knock sensor in a way that would visually show you knocking or pinging (inside the car) but it wouldn't tell the ECU. Maybe an LED or something that would come on in the event of knocking or pinging?
07-18-2003, 01:08 PM
#17
Dyno plot says I have the most area under the Administrator curve
Thread Starter
Join Date: Jul 2001
Posts: 7,060
Originally posted by BSwithTF
Here's my question though: If we do the knock sensor bypass, is there any way to continue to use the existing knock sensor in a way that would visually show you knocking or pinging (inside the car) but it wouldn't tell the ECU. Maybe an LED or something that would come on in the event of knocking or pinging?
Here's my question though: If we do the knock sensor bypass, is there any way to continue to use the existing knock sensor in a way that would visually show you knocking or pinging (inside the car) but it wouldn't tell the ECU. Maybe an LED or something that would come on in the event of knocking or pinging?
takes the knock sensor out of the control loop. Your ears will alert you to any pinging, and because the KS is out of the loop, nothing will tell the ECU except you. If you hear pinging and it gets bad, you can tell the ECU about it by going and pulling out the bypass resistor. And the only reason to bypass the knock sensor is if it's broken anyways, so keeping a broken knock sensor in some sort of control loop is not going to be of much use.
07-19-2003, 02:19 PM
#19
Dyno plot says I have the most area under the Administrator curve
Thread Starter
Join Date: Jul 2001
Posts: 7,060
Re: question...
Originally posted by JsL
I don't think my KS is bad and there is no ghost code, but when I punch the gas (about 1/2 throttle) after a stop light, it knocks once. There is no knock any other time. Is that normal?
I don't think my KS is bad and there is no ghost code, but when I punch the gas (about 1/2 throttle) after a stop light, it knocks once. There is no knock any other time. Is that normal?
06-22-2004, 07:04 AM
#23
Hmm, My car is a 99 and nearing 50k miles, and it also sometimes has iffy acceleration. Sometimes i can do manuvers, where the car rockets, and sometimes it doesnt have the omph. But its such a ***** to replace on my 99. funny thing is, there are no ghost codes.
06-22-2004, 11:56 AM
#25
Steve, excellent write up and I love the graphs - nothing says it like a graph. I have a question though. I've been thinking about doing a K.S. bypass/mod myself, to retard the timing when I spray. I thought that the peizoelectric K.S. would generate its own voltage and the ECU reads this to make its calculations. So I assume with the resistor, the ECU doesn't detect any voltage and only sees the end of line resistance - do you have any idea if I could put a different resistor in, on a switch, that would retard my timing enough to spray a 50 shot?
06-22-2004, 02:55 PM
#26
Supporting Maxima.org Member
iTrader: (15)
Join Date: Feb 2003
Location: Los Angeles, CA
Posts: 3,431
what do the jwt and technosquare ecu's ramp up our timing to? so stock it should be 15-25 @WOT depending on the RPM...I am curious to see what it should be with the JWT or technosquare...
06-22-2004, 05:42 PM
#27
Donating Maxima.org Member
Join Date: Apr 2003
Posts: 405
Cool thorough info there. Now you got me wondering.
Maybe this was covered, but anyone see something that connect via serial or CF slot for a Pocket PC? Or better yet, whats the cheapest/best solution for reading obd-ii stuff on a pocket pc?
I have 2 pocket pc's and can't really afford a palm one right now. Thanks.
Maybe this was covered, but anyone see something that connect via serial or CF slot for a Pocket PC? Or better yet, whats the cheapest/best solution for reading obd-ii stuff on a pocket pc?
I have 2 pocket pc's and can't really afford a palm one right now. Thanks.
09-09-2006, 07:43 PM
#33
Newbie - Just Registered
Join Date: May 2006
Posts: 9
Can a dead ks cause the engine to hesitate and also cut off when idling? Can the O2 sensor cause the engine to run crappy and cut off sometimes.i changed my spark plugs but the car doesnt pull right and it hesitates sometimes.when at a light it will just start idling like its dieing then it will shut off.Can anyone tell me what this can be caused by.
09-09-2006, 09:19 PM
#34
Originally Posted by Ddogstyle2
Can a dead ks cause the engine to hesitate and also cut off when idling? Can the O2 sensor cause the engine to run crappy and cut off sometimes.i changed my spark plugs but the car doesnt pull right and it hesitates sometimes.when at a light it will just start idling like its dieing then it will shut off.Can anyone tell me what this can be caused by.
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